Overview: During months of having to stay at home, millions of us have swapped the gym for our living room. The numbers doing home workouts has doubled in a year. But exactly what kind of exercise should we be doing, how much of it, and how often? Journalist and blogger Mehreen Baig used to hit the gym four times per week, but now her fitness regime has gone entirely DIY. She wants to use the latest science to make sure she is getting maximum return for her effort. With the help of former GB athlete Becky Lyne, Mehreen tries out some experimental new tech that could help us all transform our running technique, and she discovers how to choose a sports bra that can reduce painful movement by as much as 73 per cent. She investigates whether popular supplements like pre-trainers and protein shakes really work – and discovers some hidden ingredients we should all avoid. In a final experiment, she tests her own body to reveal how pursuing the perfect six-pack body shape can damage your health.